January 2018: A Painting Prep Tip

For many of us, the appeal of this hobby is in finding interesting, old iron and restoring it. That includes cleaning, repairing, and painting the machinery. One required step in preparing for paint is to mask off the machined areas that don’t need paint.

Instead of covering things with tape and then cutting around the edges with a razor, I use two tools to cut away the excess tape: a fine tooth file, preferably well-worn and dull, and a hardened pin punch. Actually, most any round piece of steel will do in place of the punch, as long as it’s hard or chrome plated.

I trim the excess tape by rubbing the tools along the sharp edges between the machined and cast areas of the part. I use both tools interchangeably, as needed.

The file works best when you have good access. Just drag it lightly along the edge at a shallow angle. You aren’t trying to file, just breaking the edge of the tape. Sometimes it works better dragging the file the wrong way, so the back of the teeth do the cutting.

The punch works better when you are working something with a shallow drop-off, such as the large round boss pictured. Just rubbing the punch along the edge will separate the tape.

Using the two methods, the trimming is fast and easy and you can quickly get on with the fun part – making the parts pretty!